Chute tube for transferring particles

ABSTRACT

A chute tube for facilitating particle transfer and distribution. The chute tube for transferring particles has a charging chute tube with a charge inlet of particles, a discharging chute tube and an intermediate chute tube slantingly connected between the charging chute tube and the discharging chute tube. The intermediate chute tube includes a groove without steps formed by a combination of a first inclined surface and a second inclined surface, and the groove is of a cross-sectional shape corresponding to two adjacent sides of a triangle.

FIELD OF THE INVENTION

The present invention relates to, in some aspects thereof, a chute tubefor transferring particles, a particle transfer apparatus including thechute tube for transferring particles, and a method for processingparticles using the particle transfer apparatus.

BACKGROUND OF THE INVENTION

As means for transferring particles, chute tubes are widely used. FIG. 4of JP-B 5840870 shows a chute, a transfer conveyor, and a transferportion provided with a bucket conveyor for transferring hydrogenatedpetroleum resin pellets. The chute is described such that it is inclinedat an angle in the range of 44 degrees to 75 degrees relative to ahorizontal surface and a plurality of buffer plates are attachedthereto.

JP-A S60-36207 discloses an invention of a gutter-shaped transferapparatus provided with a transfer chute disposed to be inclineddownwardly from one end toward the other, wherein a plurality of stepsare formed on a transfer surface of the transfer chute at predeterminedintervals in a transfer direction. The cross section of the transfersurface of the transfer chute of this transfer apparatus is V-shape andthe transfer surface is capable of reducing the friction at the time oftransferring by combination with the plurality of steps, and it isspecially used for transferring popsicles.

SUMMARY OF THE INVENTION

The object of the present invention is to provide, in some illustrativeaspects thereof, a chute tube for transferring particles which can beused for particle transfer and distribution tasks, a particle transferapparatus including the chute tube for transferring particles, and amethod for processing particles using the particle transfer apparatus.

The present invention provides, in one embodiment thereof, a chute tubefor transferring particles including at least the following intermediatechute tube from among:

a charging chute tube having a charge inlet of particles;

a discharging chute tube located at a position vertically lower andhorizontally different than the charging chute tube and connected to asubsequent unit having one or two or more functions selected from afunction of distributing particles, a function of classifying particlesand a function of conveying particles; and

an intermediate chute tube which can be connected between the chargingchute tube and the discharging chute tube in a slanting direction;

wherein the intermediate chute tube includes a groove without stepsformed by a combination of a first inclined surface and a secondinclined surface, and

the groove is of a cross-sectional shape corresponding to two adjacentsides of a triangle.

The present invention provides, in another embodiment, a particletransfer apparatus including the chute tube for transferring particles,the apparatus being capable of transferring particles and performingprocesses according to the function of the subsequent unit.

The present invention provides, in still another embodiment, a methodfor processing particles using the particle transfer apparatus. In thisprocessing method, the subsequent unit may be a divider for distributingparticles, a screen for classifying particles, a conveyor for conveyingparticles or a combination thereof. The processing method may include afirst stage of charging particles to the chute tube for transferringparticles and a second stage of delivering the particles through theintermediate chute tube to the divider, the screen or the conveyor, anddistributing the particles to each of a plurality of transfer pipes at adesired proportion amount, classifying the particles or conveying theparticles, wherein when the particles pass through the intermediatechute tube in the second stage, all the particles move along the grooveformed by the combination of the first inclined surface and the secondinclined surface and are introduced to the divider, the screen or theconveyor, and thereafter distributed, classified or conveyed. Duringuse, the chute tube may be arranged such that the groove is located at avertically lower position.

Additional embodiments of the present invention will be described belowand also explained based on the accompanying drawings.

The chute tube for transferring particles of the present invention cantransfer particles as it concentrates them into a narrow flow by thefunction of the intermediate chute tube, so that, for example, theparticles can be easily distributed at desired proportions in a divider,and in addition, the particles can be evenly introduced to a subsequentunit such as a screen or a conveyor, thereby enabling the subsequentunit to appropriately exhibit its performance. In addition, the particletransfer apparatus including the chute tube for transferring particlesof the present invention is capable of appropriately performing theparticle transfer and processes according to the function of thesubsequent unit. Furthermore, with the method for processing particlesusing such a particle transfer apparatus, a process such as particledistribution, classification or conveyance can be appropriately andreadily performed without any inconvenience such as damage to particles.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a front view of a particle transfer and distribution apparatusaccording to one illustrative embodiment including a chute tube fortransferring particles of the present invention.

FIG. 2 illustrates cross-sectional views along the II-II line of FIG. 1viewed in the direction indicated by the arrows, and each of FIG. 2(a)to FIG. 2(c) shows an illustrative embodiment with a differentcross-sectional shape.

In FIG. 3 , FIG. 3(a) is a plan cross-sectional view in which flowrectifying plates are arranged on an intermediate chute tube with thecross-sectional shape of FIG. 2(a), and FIG. 3(b) is a width-directionalcross-sectional view of FIG. 3(a).

FIG. 4 is an exploded plan view of the flow rectifying plate used inFIG. 3 .

FIG. 5 is a plan cross-sectional view of an intermediate chute tube inwhich the flow rectifying plates are arranged differently from FIG. 3 .

EMBODIMENTS OF THE INVENTION

<Chute Tube for Transferring Particles and Particle Transfer ApparatusUsing the Same>

Referring to the drawings, a chute tube for transferring particles(hereinafter, simply referred to as “chute tube”) of the presentinvention is described. In an illustrative embodiment shown in FIG. 1 ,a chute tube 1 includes a charging chute tube 10, an intermediate chutetube 20 and a discharging chute tube 35.

In the present invention, the intermediate chute tube 20 is essential,and the charging chute tube 10 and the discharging chute tube 35 may beoptionally used by combination with the intermediate chute tube 20depending on a difference in height between units connected by the chutetube 1. While a material of the chute tube 1 is not particularly limitedand a metal such as stainless steel, synthetic resin or the like may beused, stainless steel is preferable in some examples. The size of thechute tube 1 or the thickness of the tube wall is not particularlylimited and can be appropriately adjusted according to the flow rate ofparticles transferred or the strength required.

The type of particles to be transferred and distributed in the chutetube 1 is not particularly limited and may be an organic matter or aninorganic matter. The particles of interest may be spherical particlesor approximately spherical particles of a particle size which may be inthe range of 0.5 mm to 10 mm in one example, and in the range of 0.5 to5 mm in another example. In one non-limiting embodiment, the particlesmay be hygroscopic particles. For example, the chute tube 1 can beapplied to the transportation of urea particles. In one example, theurea particles may be urea particles of a particle size substantially inthe range of 0.5 to 5 mm.

The upper side of the charging chute tube 10 includes a charge inlet 11from which particles to be transferred and distributed are charged. Asfor the charge inlet 11, an end opening portion of the charging chutetube 10 may be used as a charge inlet, and in addition, the end openingportion may be expanded as necessary or a funnel-shaped separate membermay be attached thereto to facilitate the charge of particles. When theseparate member is applied as a charge inlet 11, the charge inlet 11 maybe fixed to the charging chute tube 10 or may be detachable.

A width-directional cross-sectional shape of the charging chute tube 10is not particularly limited as long as the charging chute tube 10 can beconnected to the intermediate chute tube 20. According to some examples,this cross-sectional shape is preferably a quadrangle from amanufacturing point of view. While the charging chute tube 10 isdisposed such that a central axis in the longitudinal direction of thetube is oriented in a vertical direction (the X-direction in FIG. 1 ),it may be disposed such that the central axis is oriented in a slantingdirection (a slanting direction relative to the X-direction in FIG. 1 ).

The length of the charging chute tube 10 may be adjusted according to adifference in height between units connected via the chute tube 1 and insome examples, it is preferable that it should be substantially shorterthan the length of the intermediate chute tube 20. Note that, in thedrawings, each member does not necessarily reflect its actual size.

Note that the charge inlet 11 is connected to the intermediate chutetube 20 when the charging chute tube 10 is not provided. The way andconfiguration of the connection may be the same as those in the casewhere the charge inlet 11 is connected to the charging chute tube 10.

In the embodiment shown in FIG. 1 , the discharging chute tube 35 islocated at a position vertically lower and horizontally (in theY-direction in FIG. 1 and the direction perpendicular to theX-direction) different than the charging chute tube 10. While in theillustrated example, the discharging chute tube 35 is disposed such thata central axis in the longitudinal direction of the tube is oriented ina vertical direction (the X-direction in FIG. 1 ), it may be disposedsuch that the central axis is oriented in a slanting direction (aslanting direction relative to the X-direction in FIG. 1 ).

A width-directional cross-sectional shape of the discharging chute tube35 may be any shape as long as the discharging chute tube 35 can beconnected to the intermediate chute tube 20 and a divider 40. Accordingto some examples, this cross-sectional shape is preferably a quadranglefrom a manufacturing point of view. The length of the discharging chutetube 35 may be adjusted according to a difference in height betweenunits connected via the chute tube 1 and in some examples, it ispreferable that it should be substantially shorter than the length ofthe intermediate chute tube 20.

In the particle transfer and distribution apparatus shown in FIG. 1 ,the discharging chute tube 35 can be connected to the divider 40 havinga function of distributing particles. When the discharging chute tube 35is not provided, the divider 40 can be connected to the intermediatechute tube 20.

While in the embodiment shown in FIG. 1 , the intermediate chute tube 20is connected to the divider 40 via the discharging chute tube 35, and inanother embodiment, the intermediate chute tube 20 can be connecteddirectly or via the discharging chute tube 35 to a screen having afunction of classifying particles. In another embodiment, theintermediate chute tube 20 can also be connected directly or via thedischarging chute tube 35 to a different subsequent unit such as aconveyor having a function of conveying particles. In addition, in stillanother embodiment, a combination of a plurality of units such as thedivider 40, a screen and a conveyor may also be used as a subsequentunit.

In the embodiment shown in FIG. 1 , the intermediate chute tube 20 isconnected between the charging chute tube 10 and the discharging chutetube 35 in a slanting direction. As mentioned above, when the chargingchute tube 10 is not provided, the intermediate chute tube 20 isconnected between the charge inlet 11 and the discharging chute tube 35in a slanting direction; when the discharging chute tube 35 is notprovided, the intermediate chute tube 20 is connected between thecharging chute tube 10 and the divider 40 in a slanting direction; andwhen both the charging chute tube 10 and the discharging chute tube 35are not provided, the intermediate chute tube 20 is connected betweenthe charge inlet 11 and the divider 40 in a slanting direction.

In an illustrative embodiment, an angle (α) formed between theintermediate chute tube 20 and a horizontal direction (the Y-directionof FIG. 1 ) may be in the range of 30 degrees or more and less than 90degrees and is preferably in the range of 40 degrees to 60 degrees.

Referring to FIG. 2(a) to FIG. 2(C), cross-sectional views along theII-II line of FIG. 1 viewed in the direction indicated by the arrows,the intermediate chute tube 20 includes a groove 23 without steps formedby a combination of a first inclined surface 21 and a second inclinedsurface 22. The groove 23 is located at a vertically lower position inthe intermediate chute tube 20. In other words, the groove 23 extendsalong the bottom of the intermediate chute tube 20 which extends in aslanting direction.

In an illustrative embodiment of the present invention, both the firstinclined surface 21 and the second inclined surface 22 are flat surfacesand the groove 23 includes no steps, specifically, steps in thelongitudinal direction of the intermediate chute tube 20 or a particletransfer direction. If the groove 23 includes steps, particles may comein contact with corner portions formed by the steps in the inner surfaceof the chute tube, thereby causing a problem that particles, i.e.,products are damaged and accompanying dust may readily be producedtherefrom. The problem becomes more prominent when the hardness ofparticles transferred is lower.

The groove 23 is configured such that the cross-sectional shape thereofis a shape corresponding to two adjacent sides of a triangle, therebyconcentrating transferred particles to the groove 23. In someillustrative embodiments, the intermediate chute tube 20 including thegroove 23 is preferably of any form of the following first form to thirdform.

(First Form)

A form, when viewed in a cross-sectional shape as illustratively shownin FIG. 2(a), in which one side of a quadrangle such as a rectangle or asquare is shaped as it corresponds to two adjacent sides of a triangle(two sides corresponding to the first inclined surface 21 and the secondinclined surface 22) (a home-plate shape). The first form shown in FIG.2(a) includes a first side-wall surface 20 a extended from the firstinclined surface 21, a second side-wall surface 20 b extended from thesecond inclined surface 22, the second side-wall surface 20 b beingopposed to the first side-wall surface 20 a in the width direction, anda top surface 20 c located between the first side-wall surface 20 a andthe second side-wall surface 20 b.

(Second Form)

A form, when viewed in a cross-sectional shape as illustratively shownin FIG. 2(b), in which a square is disposed such that any one of thecorners (a portion corresponding to the groove 23) is located at avertically (in the X-direction of FIG. 1 ) lower position. The secondform shown in FIG. 2(b) includes, in addition to the first inclinedsurface 21 and the second inclined surface 22, a first inclined topsurface 20 d on the first inclined surface 21 side and a second inclinedtop surface 20 e on the second inclined surface 22 side. The firstinclined top surface 20 d and the second inclined top surface 20 e areinterconnected. Note that, while FIG. 2(b) shows a square, it is notlimited to a square and may be a rectangle or other quadrangles.

(Third Form)

A form, when viewed in a cross-sectional shape as illustratively shownin FIG. 2(c), in which a regular triangle is disposed such that any oneof the corners (a portion corresponding to the groove 23) is located ata vertically (in the X-direction of FIG. 1 ) lower position. The thirdform shown in FIG. 2(c) includes, in addition to, the first inclinedsurface 21 and the second inclined surface 22, a top surface 20 fstretched therebetween. While FIG. 2(c) shows a regular triangle, it isnot limited to a regular triangle and may be an isosceles triangle orother triangles.

In some illustrative embodiments, an angle of the groove 23 in across-sectional shape (an angle formed between the first inclinedsurface 21 and the second inclined surface 22) may be equal to orgreater than the angle of repose of particles to be transferred in orderto prevent the particles from being stagnant, and is preferably 45degrees to 130 degrees.

According to some illustrative embodiments, a plurality of flowrectifying plates may be arranged in one of or both the first inclinedsurface 21 and the second inclined surface 22 of the intermediate chutetube 20 for narrowing the width of the groove 23 so that the particlesflow in a narrower width within the groove 23. In an example shown inFIGS. 3(a) and (b), on the first inclined surface 21 and the secondinclined surface 22 of the intermediate chute tube 20, respectively,first flow rectifying plates 25 and second flow rectifying plates 30 arearranged in pairs at widthwise opposing positions (in bilateral symmetryin the longitudinal direction) of the intermediate chute tube 20. Forexample, two to ten pairs of the first flow rectifying plate 25 and thesecond flow rectifying plate 30 may be arranged.

The first flow rectifying plate 25 may be formed of, in one example, acombination of a first plate member 26 of a triangular planer shape anda second plate member 27 of a quadrangular planer shape as shown in FIG.4 , or the entire thereof may be formed of one plate member.

The first plate member 26 is preferably of an isosceles-triangularplaner shape and such an isosceles triangle includes, for example, along side 26 a, a first short side 26 b and a second short side 26 c asshown in FIG. 4 . The second plate member 27 may be, for example, aquadrangle whose four sides are different in length from one another. Inone example, as shown in FIG. 4 , the four sides are a first long side27 c, a second long side 27 a, a first short side 27 b and a secondshort side 27 d in decreasing order of their length, and the first shortside 27 b and the second short side 27 d are located at positions wherethey are mutually opposed and the first long side 27 c is located at aposition where it faces both the second long side 27 a and the firstshort side 27 b. An angle formed between the second long side 27 a andthe first short side 27 b is more than 90 degrees and an angle formedbetween the second long side 27 a and the second short side 27 d is lessthan 90 degrees.

As illustratively shown in FIG. 3(b), when the first plate member 26 isof an isosceles-triangular planer shape, the long side 26 a abuts thefirst inclined surface 21, and the first short side 26 b is arrangedbetween the first inclined surface 21 and the top surface 20 c (see FIG.2(a)) of the intermediate chute tube 20 while being spaced apart fromthe both. The first plate member 26 is arranged such that an angle β₁formed between the first plate member 26 and a direction orthogonal tothe length direction of the intermediate chute tube 20 (the widthdirection of the intermediate chute tube 20) is equal to or greater thanthe angle of repose of particles to be transferred, thereby preventingthe particles to be transferred from being stagnant.

In the illustrated example, the length of the second long side 27 a ofthe second plate member 27 is the same as that of the second short side26 c of the first plate member 26 and the second long side 27 a isarranged to make contact with the second short side 26 c. The firstshort side 27 b of the second plate member 27 is arranged to makecontact with the first inclined surface 21, and the second short side 27d is arranged between the first inclined surface 21 and the top surface20 c of the intermediate chute tube 20 while being spaced apart from theboth.

The second plate member 27 is arranged such that the entire thereof isalong the same direction as the length direction of the intermediatechute tube 20. Surfaces at which connecting surfaces of the first platemember 26 and the second plate member 27 make contact with each other(the surface of the second short side 26 c of the first plate member 26and the surface of the second long side 27 a of the second plate member27) and surfaces at which the first plate member 26 and the second platemember 27 make contact with the first inclined surface 21 (the surfaceof the long side 26 a of the first plate member 26 and the surface ofthe first short side 27 b of the second plate member 27) are eachpreferably processed such that the contact surfaces are formed asinclined surfaces that enable to make tight contact with each other.

In the illustrated example, the second flow rectifying plate 30 isarranged at a position where it is opposed to the first flow rectifyingplate 25 in the width direction (in bilateral symmetry in thelongitudinal direction) of the intermediate chute tube 20 and the shapeof the second flow rectifying plate 30 is the same as that of the firstflow rectifying plate 25 except that they are opposite in orientation.While the second flow rectifying plate 30 may be formed of a combinationof a third plate member 31 of a triangular planer shape and a fourthplate member 32 of a quadrangular planer shape as shown in FIG. 4 , theentire thereof may also be formed of one plate member.

The third plate member 31 is preferably of an isosceles-triangularplaner shape and such an isosceles triangle includes, for example, along side 31 a, a first short side 31 b and a second short side 31 c asshown in FIG. 4 . The fourth plate member 32 may be a quadrangle whosefour sides are different in length from one another. In one example, asshown in FIG. 4 , the four sides are a first long side 32 c, a secondlong side 32 a, first short side 32 b and a second short side 32 d indecreasing order of their length, and the first short side 32 b and thesecond short side 32 d are located at positions where they are mutuallyopposed and the first long side 32 c is located at a position where itfaces both the second long side 32 a and the first short side 32 b. Anangle formed between the second long side 32 a and the first short side32 b is more than 90 degrees and an angle formed between the second longside 32 a and the second short side 32 d is less than 90 degrees.

As illustratively shown in FIG. 3(b), when the third plate member 31 isof an isosceles-triangular planer shape, the long side 31 a abuts thesecond inclined surface 22, and the first short side 31 b is arrangedbetween the second inclined surface 22 and the top surface 20 c of theintermediate chute tube 20 while being spaced apart from the both. Thethird plate member 31 is arranged such that an angle β₂ formed betweenthe third plate member 31 and a direction orthogonal to the lengthdirection of the intermediate chute tube 20 (the width direction of theintermediate chute tube 20) is equal to or greater than the angle ofrepose of particles to be transferred, thereby preventing the particlesto be transferred from being stagnant.

In the illustrated example, the length of the second long side 32 a ofthe fourth plate member 32 is the same as that of the second short side31 c of the third plate member 31 and the second long side 32 a isarranged to connect with the second short side 31 c. The first shortside 32 b of the fourth plate member 32 is arranged to make contact withthe second inclined surface 22, and the second short side 32 d isarranged between the second inclined surface 22 and the top surface 20 cof the intermediate chute tube 20 while being spaced apart from theboth.

The fourth plate member 32 is arranged such that the entire thereof isalong the same direction as the length direction of the intermediatechute tube 20. Surfaces at which connecting surfaces of the third platemember 31 and the fourth plate member 32 make contact with each other(the surface of the second short side 31 c of the third plate member 31and the surface of the second long side 32 a of the fourth plate member32) and surfaces at which the third plate member 31 and the fourth platemember 32 make contact with the second inclined surface 22 (the surfaceof the long side 31 a of the third plate member 31 and the surface ofthe first short side 32 b of the fourth plate member 32) are eachpreferably processed such that the contact surfaces are formed to beinclined surfaces that enable to make tight contact with each other.

While the first flow rectifying plate 25 and the second flow rectifyingplate 30 used in the illustrated example may be made of a metal orsynthetic resin, in some examples, the material of them is preferablythe same as that of the intermediate chute tube 20.

In some illustrative embodiments, the first flow rectifying plate 25 andthe second flow rectifying plate 30 may be attached by fitting them intoattachment slots which are previously formed in the first inclinedsurface 21 and the second inclined surface 22. In that case, theintermediate chute tube 20 may be configured to be dividable into twohalves, or when it is in the form of FIG. 2(a), the top surface 20 c maybe configured to be detachable.

In addition, when the intermediate chute tube 20, the first flowrectifying plate 25 and the second flow rectifying plate 30 are, forexample, made of stainless steel, either of the following methods may beapplied: a method of fixing the first flow rectifying plate 25 and thesecond flow rectifying plate 30 to the intermediate chute tube 20 bywelding; or a method of fitting the first flow rectifying plate 25 (thefirst plate member 26 and the second plate member 27) and the secondflow rectifying plate 30 (the first plate member 31 and the second platemember 32) into the attachment slots as mentioned above and thereafterfixing them by welding.

Note that, in some illustrative embodiments, unless affecting theparticle transfer, the first plate member 26 and the second plate member27 of the first flow rectifying plate 25 do not need to be connected bywelding or the like as long as they make contact with each other.Similarly, in that case, the first plate member 31 and the second platemember 32 of the second flow rectifying plate 30 do not need to beconnected by welding or the like either.

In the illustrative embodiment shown in FIG. 3 , as the shape of thegroove 23 formed by the first inclined surface 21 and the secondinclined surface 22 is a tapered shape at the portion provided with thefirst flow rectifying plate 25 and the second flow rectifying plate 30,which are arranged to be opposed to each other in the width direction ofthe intermediate chute tube 20, the flow of the particles to betransferred can be rectified to a narrower range and delivered to thedivider 40 (or a subsequent unit such as a screen or conveyor).

FIG. 5 shows a plan cross-sectional view of an intermediate chute tubein which the flow rectifying plates are arranged differently from FIG. 3. In this example, in the first inclined surface 21 and the secondinclined surface 22 of the intermediate chute tube 20, respectively, thefirst flow rectifying plates 25 and the second flow rectifying plates 30are alternately arranged in the length direction. Except for that, theexample of FIG. 5 may be the same as FIG. 3 .

Again referring to FIG. 1 , in some illustrative embodiments, thedivider 40 for distributing particles is connected to a discharge outletof the discharging chute tube 35, and the first transfer pipe 51 and thesecond transfer pipe 52 for transferring particles distributed at thedivider 40 are connected to the divider 40. When a screen or a conveyoris used as a subsequent unit, the screen or the conveyor may beconnected thereto instead of the divider 40.

<Method for Processing Particles>

An illustrative method for processing particles using the particletransfer apparatus shown in FIG. 1 is described. With the processingmethod of the illustrative embodiment of the present invention, alongwith particle transfer, processes according to the function of asubsequent unit can be performed. This processing method may include afirst stage and a second stage. The subsequent unit may be, for example,a divider for distributing particles, a screen for classifyingparticles, a conveyor for conveying particles or a combination thereof.

The first stage is a stage of charging particles to be processed to thechute tube 1 for transferring particles. The charge of particles may beperformed by charging a predetermined amount of particles, which are,for example, conveyed with a liftable bucket, to the charge inlet 11connected to the charging chute tube 10.

The second stage is a stage of delivering the particles charged from thecharge inlet 11 through the charging chute tube 10, the intermediatechute tube 20 and the discharging chute tube 35 to the divider 40 andfurther distributing the particles to each of the first transfer pipe 51and the second transfer pipe 52 at a desired proportion. When theparticles pass through the intermediate chute tube 20 in the secondstage, all the particles move along the groove 23 formed by thecombination of the first inclined surface 21 and the second inclinedsurface 22 and are introduced to the divider 40, and thereafterdistributed.

As all the particles pass through the groove 23 of the intermediatechute tube 20, they enter the divider 40 in a state concentrated into anarrow flow. Thus, the particles can be introduced around the center ofthe divider 40, so that the particles are easily distributed at adesired proportion to each of the first transfer pipe 51 and the secondtransfer pipe 52 when they are distributed at the divider 40. When thefirst flow rectifying plate 25 and the second flow rectifying plate 30are provided, this function can be further enhanced.

A distribution proportion for each of the first transfer pipe 51 and thesecond transfer pipe 52 can be in the range of 0% to 100% of the totalamount of the particles. Further, in the method of particle transfer anddistribution or other processing of the present invention, even ifparticles of a small specific gravity or particles of a small particlesize, which may not be considered to be readily concentrated into anarrow flow, are used, the function of the groove 23 of the intermediatechute tube 20 allows the particles to be introduced to the divider 40 ina state concentrated into a narrow flow, thereby facilitating thedistribution.

For example, when a screen having a function of classifying particles isused instead of the divider 40, the particles can be fed to the centerof the screen in a concentrated state. The introduced particles areevenly distributed over the screen surface so that the entire screensurface can be utilized and thus, the classifying performance can bemore easily exhibited and this is preferable. On the other hand, ifparticles are flown to one side and introduced to the screen, excessiveparticles are flown over a screen surface onto which the particle flowis directed, while a screen surface over which the particle flow isscarce dose not contribute to the classification of the particles,thereby causing a problem that a desired classifying performance is notexhibited.

In addition, for example, when a conveyor having a function of conveyingparticles is used instead of the divider 40, as the particles are fed tothe center of the conveyor in a concentrated state, preferably such aproblem that the particles spill over from a conveying surface of theconveyor does not occur.

Note that, when a gutter-shaped chute having a V-shaped cross-section aswell as having a plurality of steps along a transfer direction, which isdisclosed in JP-A S60-36207 as mentioned above, is used instead of theintermediate chute tube 20, particles may come in contact with cornerportions formed by the steps in an inner surface of the chute tube,thereby causing a problem that particles, i.e., products, are damagedand accompanying dust may readily be produced therefrom. The problembecomes more prominent when the hardness of particles transferred islower.

INDUSTRIAL APPLICABILITY

The chute tube for transferring particles and the particle transferapparatus including the same as well as the processing method of thepresent invention can be utilized for transferring particles such as,for example, urea particles, and performing processes according to thefunction of a subsequent unit combined therewith.

DESCRIPTION OF REFERENCE NUMERALS

-   1 chute tube for transferring particles-   10 charging chute tube-   11 charge inlet-   20 intermediate chute tube-   35 discharging chute tube-   40 divider-   51 first transfer pipe-   52 second transfer pipe

The invention claimed is:
 1. A chute tube device for transferringparticles, comprising: a charging chute tube having a charge inlet; adischarging chute tube located at a position vertically lower andhorizontally different than the charging chute tube and connected to atleast one of a screen, a conveyor, or a divider; and an intermediatechute tube which is connected to the charging chute tube and thedischarging chute tube in a slanting direction; wherein the intermediatechute tube comprises a groove without steps formed by a combination of afirst inclined surface and a second inclined surface, and the groove isof a cross-sectional shape corresponding to two adjacent sides of atriangle, and one or more flow rectifying plates are arranged on thefirst inclined surface and the second inclined surface of theintermediate chute tube for narrowing the width of the groove tofacilitate the particles flow centrally of the groove.
 2. The chute tubedevice for transferring particles according to claim 1, wherein theintermediate chute tube including the groove has a cross-sectional shapeselected from: a first form of a quadrangle in which one side of thefirst form quadrangle is shaped to correspond to two adjacent sides of atriangle; a second form of a quadrangle in which the second formquadrangle is disposed such that any one of the corners is located at avertically lower position than the other corners; and a third form of atriangle in which the triangle is disposed such that any one of thecorners is located at a vertically lower position than the othercorners.
 3. The chute tube device for transferring particles accordingto claim 1, wherein an angle formed by the two adjacent sides of thetriangle in the cross-sectional shape of the groove is 45 degrees to 130degrees.
 4. The chute tube device for transferring particles accordingto claim 1, wherein an angle formed between a central axis of theintermediate chute tube and a horizontal direction is in the range of 30degrees or more and less than 90 degrees.
 5. The chute tube device fortransferring particles according to claim 1, further comprisingparticles therein, the particles being hygroscopic particles.
 6. Thechute tube device for transferring particles according to claim 1,further comprising particles therein, the particles being urea particlesof a particle size in the range of 0.5 to 5 mm.
 7. The chute tube devicefor transferring particles according to claim 1, wherein the one or moreflow rectifying plates are arranged such that an angle formed betweenthe one or more flow rectifying plates and a direction orthogonal to alength direction of the intermediate chute tube is equal to or greaterthan an angle of repose of particles to be transferred, therebypreventing the particles to be transferred from being stagnant.
 8. Amethod for processing particles using the chute tube device of claim 1,the method comprising: charging particles to the chute tube device fortransferring particles; and delivering the particles through theintermediate chute tube to the screen, the conveyor, or the divider, anddistributing the particles to each of a plurality of transfer pipes at adesired proportion amount, classifying the particles or conveying theparticles, wherein when the particles pass through the intermediatechute tube, all the particles move along the groove formed by thecombination of the first inclined surface and the second inclinedsurface and are thereby directed to the screen, the conveyor, or thedivider.